<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
	</head>
	<body>
		
	</body>
</html>
<script>
	var str="JavaScript";
	console.log(str.length);
	
	console.log(str.match(/[A-Z]/g));
	console.log(str.match("java"));
	
	console.log(str.replace("J","j"));
	console.log(str.replace(/S/,"s"));
	var s1="北京|上海|广州";
	
	console.log(s1.split("|"));
	console.log(str.substring(0,2));
	console.log(str.substring(4));
	
</script>